P0650
Malfunction Indicator Lamp Control Circuit Malfunction
A fault in the wiring or control circuit between the ECU and the malfunction indicator lamp (MIL). The MIL may stay on permanently, fail to light at key-on, or flicker — the OBD-II self-check on the bulb itself failed.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Common causes
Ordered by how often each turns out to be the cause.
- MIL bulb burnt out (older clusters)Possible
- Instrument cluster MIL driver failedPossible
- Wiring fault between ECU and clusterLess likely
Parts involved
- MIL Lamp
- MIL Wiring
- Instrument Cluster
P0650 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.